<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      .box {
        height: 0px;
        width: 0px;
        border: 20px transparent solid;
        border-bottom-color: blue;
      }

      .circle {
        background-color: red;
        height: 100px;
        width: 100px;
        border-radius: 50%;
      }

      .diamond {
        margin-left: 50px;
        width: 200px;
        height: 200px;
        transform: rotate(45deg);
        background-color: coral;
      }
    </style>
  </head>
  <body>
    <div class="box"></div>
    <div class="circle"></div>
    <div>
      <div class="box"></div>
      <div
        class="box"
        style="border: 20px transparent solid; border-top-color: blue"
      ></div>
    </div>
    <div class="diamond"></div>
  </body>
</html>
